My house is 90 feet wide. Two full baths on a 40 gallon on the west
side of the house. Master bath, laundry equipment and kitchen on a 50
gallon on the east side of the house. Both natural gas fueled. The only
time we ran out of hot water was on the west side when older son stayed
in the shower forever. When it turned cold, he got out. Has not
repeated since he left home.
The dishwasher and kitchen sink are farthest from the water heater and
take some time to get hot water coming out.